preflop: what are the kinds of hands is he likely to call 3bet with? probably big broadways such as AK, AQ, maybe some big pairs as well like JJ, or QQ (i think KK and AA would 4bet me already)

i really didnt want to see that last heart on the river, and i guess that's really what he wants to rep. but how likely is it that he has FD with such a line? plus i have blockers to AA and JJ as well as to the flush. im doubting he has 44 or 66 because he deffo wouldv raised me sometime before with all the scary draws out there.

i really sweated out this river.

edit: more reads on him- on a previous hand, he gives up initiative as initial raiser and just insta check/folds. his cbet is only 49%

If you don't expect him to defend KQ type hands than you should call the river. He has 0 flushed in his range.

However, without enough info on the guy we shouldn't assume he doesn't defend light like 89-KQ hh. We have a lot of hands on him so we should have an idea about his calling range.

As played, I prefer a bigger bet on the turn as his range becomes very inelastic. In my mind he either continues or he doesn't (this is assuming he doesn't know anything about our bet sizings - which I doubt that he does).

On the river his range could be hands like AQ/AK some A4/A6 (suited) and flush draws. It's hard to imagine many worse Ax hands raising river (as opposed to turn). So that leaves him with the made flushes.

So given how the hand got played I can't see much of an option. Unless he has been a spew monkey we see a flush here more often than anything else. Our pot odds are 20% (1 in 5) so I can't really see him doing this as a weaker vbet or bluff often enough.